As disclosed in Manning U.S. Pat. No. 4,021,073, it has heretofore been proposed to combine a ventilator and escape hatch for a roof of a bus or other vehicle by hingedly connecting a lid to opposite sides of a frame bounding an opening in a vehicle roof for a limited opening movement relative to one or more sides of the frame and forming at least one of the connections of separable parts, one connected to the lid and the other to the frame. In Manning the separable lid and frame parts are oppositely extending, normally overlapping web portions the outer end of each of which normally fits in a U-shaped section in the other part and the parts are normally connected by projections or spurs on a lever hinged to the lid part that are adapted to extend through then-aligned apertures in the web portions of both parts. A spring acting downwardly between the lid and the operating arm of the lever yieldably holds the projections in the aperture and withdrawal of the projections from the apertures by pressing the lever arm upwardly against the lid, enables the parts to be separated and the lid swung about the hinged connection at the opposite side of the frame for converting the roof opening into a fully openable escape hatch.
The principal concern in the present invention is an improvement on the combined vent and escape hatch of the Manning patent.